Radioiodinated vectors are valuable tools for therapeutic, medical diagnostic imaging and research. For example, 123I labeled vectors are used for SPECT imaging, 124I labeled vectors are used PET imaging, 125I labeled vectors are used for biological assays and therapy and 131I labeled vectors are used for therapy.
Radioiodination (see Scheme 1, below) can be achieved by treatment of a vinyl or aryl-tin precursor (“Prec”) with a radioiosotope of iodide (e.g., an 123I− species) under oxidative conditions to yield the desired radioiodinated product (“I-Prod”) and a tin cleavage product (“C”). Excess aryl-tin precursor is used to ensure fast and efficient utilization of the radioactive iodide.
Typically, HPLC is required to separate the desired radioiodinated product from the tin cleavage product and unreacted aryl-tin precursor. However, HPLC is time consuming, thus resulting in a loss of activity, and also generally requires significant investment, space and trained personnel.